Solve for $x$ and $y$ using substitution. ${x-5y = 8}$ ${y = -x+2}$
Solution: Since $y$ has already been solved for, substitute $-x+2$ for $y$ in the first equation. ${x - 5}{(-x+2)}{= 8}$ Simplify and solve for $x$ $x+5x - 10 = 8$ $6x-10 = 8$ $6x-10{+10} = 8{+10}$ $6x = 18$ $\dfrac{6x}{{6}} = \dfrac{18}{{6}}$ ${x = 3}$ Now that you know ${x = 3}$ , plug it back into $\thinspace {y = -x+2}\thinspace$ to find $y$ ${y = -}{(3)}{ + 2}$ $y = -3 + 2$ $y = -1$ You can also plug ${x = 3}$ into $\thinspace {x-5y = 8}\thinspace$ and get the same answer for $y$ : ${(3)}{ - 5y = 8}$ ${y = -1}$